FEATURES
o
16,384 Bit Ultraviolet Erasable, Electrically Program-mable ROM, organized as 2048 words by 8 bitso
Single +5 volt power supply during READ operation o Fast Access Time in READ modeo
Low Power Dissipation: 525mW max activeo
Power Down Mode: 132mW max standbyo
Three State Output OR-tie capability DESCRIPTIONThe MK2716 is a 2048 x 8 bit electrically program-mable/ultraviolet erasable Read Only Memory. The circuit is fabricated with Mostek's advanced N-channel silicon gate technology for the highestperformance and reliability. The MK2716 offers significant advances over BLOCK DIAGRAM
o
Five mo.des of operation for greater system flexibility (see Table)o
Single programming requirement: single location programming with one 50msec pulseo
Pin Compatible' with Mostek's BYTEWYDETM Memory Familyo
TIL compatible in all operating modeso
Standard 24 pin DIP with transparent lid MODE SELECTION*Inputs in Program Mode IV-15
ABSOLUTE MAXIMUM RATINGS*
Voltage on any pin relative to VSS (Except Vpp) ... -0.3V to +6V Voltage on Vpp supply pin relative to VSS ... -0.3V to +28V Operating Temperature TA (Ambient) ... 0°C:5 TA:5 70°C StorageTemperature (Ambient) ... -55°C:5 T A:5 +125°C Power Dissipation ... 1 Watt Short Circuit Open Current .. , . : ... 50mA
*Stresses greater than those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operating sections of this specification is not implied.-Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
READ OPERATION
RECOMMENDED DC OPERATING CONDITIONS AND CHARACTERISTICS',3,1 (O°C :5T A :5 70°C) (V CC = +5V
±
5%, Vpp = Vcel
SYM PARAMETER MIN TYP MAX
VIH Input High Voltage 2.0 VCC+1
VIL Input Low Voltage -0.1 0.8
ICC1 VCC Standby Powe~upply 10 25
Current (OE
=
VIL; CE=
VIH)ICC2 VCC Active Power Supply Current 57 100
(OE
=
CE=
VILlIpP1 Vpp Current (Vpp
=
5.25V) 6VOH Output High Voltage 2.4
(IOH
= -
4OO!LA )VOL Output Low Voltage .45
(lOL
=
2.1 mAlIlL Input Leakage Current 10
(VIN
=
5.25V)IOL Output Leakage Current 10
(VOUT
=
5.25V) AC CHARACTERISTICS',2,4(O°C :5 T A :5 70°C) (V CC
=
+5V±
5%, Vpp=
Vcel
-5 -6 -7
UNITS NOTES V
V
mA 2
mA 2
mA 2
V
V
!LA
J.LA
-8
SYM PARAMETER MIN MAX MIN MAX MIN MAX MIN MAX UNITS NOTES
tACC Address to Output Delay 300 350 390 450 ns
(CE
=
OE=
VIL)tCE CE to Output Delay 300 350 390 450 ns 5
(OE
=
VIL)tOE Output Enable to Output 120 120 120 120 ns 9
Delay (CE
=
VIL)tDF Chip Deselect to Output 0 100 0 100 0 100 0 100 ns 8
Float (CE
=
VIL)tOH Address to Output Hold 0 0 0 0 ns
(CE
=
OE=
VIL)IV-16
CAPACITANCE (TA = 25°C)
SYM PARAMETER
CIN Input Capacitance COUT Output Capacitance
NOTES:
1. Vee must be applied on or before Vpp and removed after or at the same times as Vpp.
2. Vpp and Vee may be connected together(except during programming,) in which case the supply current is the sum of ICC and IpPl. Data Outputs open.
3. All voltages with respect to VSS.
4. Load conditions::;; ITTL load and 100pF., tr = tf = 20n5. reference levels are lV or 2V for inputs and .BV and 2V for outputs.
TIMING DIAGRAMS READ CYCLE (CE
=
VIL)ADDRESSES
OE
OUTPUT
STANDBY POWER DOWN MODE (OE
=
VIL)ADDRESS
OUTPUT
OPEN
VALID
VALID FOR CURRENT ADDRESS
VOL - _ _ _ _ _ _ _ _ _ _ _ .11
STANDBY
OPEN
TYP MAX UNITS NOTES
4 6 pF 6
8 12 pF 6
5. tOE is referenced to CE or the addresses, whichever occurs last.
6. Effective Capacitance calculated from the equation C = .6.0 where l:J. V = 3V 7. Typical numbers are for
!a
= 25~and Vee = 6.0V-;;.v
8. tOF is applicable to both CE and OE, whichever occurs first.
9. 6E may follow up to tACC • tOE after the falling edge of CE without effecting tACC.
VALID
ACTIVE
VALID FOR CURRENT ADDRESS
STANDBY
IV-'-17
PROGRAM OPERATIONs
DC ELECTRICAL CHARACTERISTICS AND OPERATING CONDITIONS',2 (T A
=
25°C ± 5°C) (V cc=
5V ± 5%. Vpp=
25V ± 1 V)SYM PARAMEtER .. MIN
IlL . Input Leakage Current
VIL 'Input Low Level -0.1
VIH Input High Level 2.0
ICC Vce POVl(er Supply Current IpP1 Vpp Supply Current
IpP2 Vpp Supp,ly Current during Programming Pulse
AC CHARACTERISTICS AND OPERATING CONDITIONS',2,6,7 ',(TA = 25°C± 5°C) (Vec '= 5V ±5%}. Vpp = 25V± 1V) tOE Output Ena,ble .to OU!put Delay
tpw Program Pulse Width 45 50
B. Although speed selections are made for READ operation all programming specifications are the.same for all dash, numbers.
IV---JB
TIMING DIAGRAM
hardwirE:ldlogic';in cost: system flexibility, turnaround tinieandperformance., ' ' ' , '
The MK2716 has many useful systemoriehted features including
a
STANDBY mode of operation which lowers the device power from 5'25mW'maxim:um active power to 132mW maxim'um for an overali savings of 75%.Programming can be done with a single TTL level pulse, and may be done on any individual location either sequencially or at random, The three-state output controlled by the OE input allows OR~tie capability for construction of large arrays. A single power supply requirement of +5 volts makes the MK2716 ideally suited for use with Mostek's new 5 volt only microprocessors such as the MK3880 (Z80). The MK2716 is packaged in the industry standard 24-pin dual-in line package with a transparent hermetically sealed lid. This allows the user to expose the chip to ultraviolet light to erase the data pattern. A new pattern may then be written into the device by following the program procedures outlined in this data sheet.
The MK2716 is specifically designed to fit those applications where fast turnaround time and pattern experimentation are required. Since data may be altered in the device (erase and reprogram) it allows for early debugging of the system program. Since single location programming is available the MK2716 can
ADDRESS N ADDRESSES N + M
~---tAH---~
ADD N+ M
have ltsdata content increased (assuming all 2048 bytes wetenot programmed) 'at anytime for easy updating of system capabiliti'es in the field. Once the data/program is fixed and
the
intention is to produce large numbers of systems, Mostek a'iso supplies a pin compatible mask programmable ROM, the MK34000.To transfer the program data to ROM, the user need only send the PROM along with device information to Mostek, from which the ROM with the desired pattern can be generated. This means a reduction in the possibility of error when converting data to other forms (cards, tape, etc.) for this purpose. However, data may still be input by any of these traditional means such as paper tape, card deck, etc.
READ OPERATION
The MK2716 has five basic modes of operation. Under normal operating conditions (non-programming) there are two modes including READ and STANDBY. A READ operation is accomplished by maintaining pin 18 (CE) at VIL and pin 21 (Vpp) at +5 volts. If OE (pin 20) is held active low after addressing (AO - AlO) have stabilized then valid output data will appear on the output pins at access time tACC (address access). In this mode, access time may be referenced to OE (tOE) depending on when OE occurs (see timing diagrams).
IV-19
POWER DOWN operation is accomplished by taking pin 18(CE) to a TTL high level (VIH)' The power is reduced by 75% from 525mW maximum to 132mW. In power down Vpp must be at +5 volts and the outputs Will be open-circuit regardless of the condition ofOE. Access time from a high to low transition ofCE(tCE) is the same as from addresses (tACC)' (See STANDBY Timing Diagram).
PROGRAMMING INSTRUCTIONS
The MK2716 as shippedfrom Mostek will be completely erased. In this initial state and after any subsequent erasure, all bits will be' at a '1' level (output high).
Information is introduced by selectively programming 'O's into the proper bit locations. Once a '0' has been programmed into the chip it may be changed only by erasing the entire chip with UV light.
Word address selection is done by the same decode circuitry used in the READ mode. The MK2716 is put into the PROGRAM mode by maintaining Vpp at +25V, and OE at VIH' In this mode the output pins serve as inputs (8 bits in parallel) for the required program data.
Logic levels for other inputs and the VCC supply voltage are the same as in the READ mode.
To program a "byte" (8 bits) of data, a TTL active high level pulse is appliedtothe CE/PGM pin once addresses and data are stabilized on the inputs. Each location must have a pulse applied with only one pulse per location required. Any individual location, a sequence of locations or locations at random may be programmed in this manor. The program pulse has a minimum width of 45msec and a maximum of 55msec, and must not be programmed with a high level D.C. signal applied to the EE/PGM pin. "
PROGRAM INHIBIT is another useful mode'of operation when programming multiple parallel addressed MK2716's with different data. It is necessary only to maintain OE at VIH, Vpp at +25, allow addresses and data to stabilize and pulse the CE/PGM pin ofthe device to be programmed. Data may then be changed and the next device pulsed. The devices with CE/PGM at VIL will not be programmed.
PROGRAM VERIFY allows the MK2716 program data to be verified without having to reduce Vpp from +25V to +5V. Vpp ,should only be used in the PROGRAMI PROGRAM INHIBIT and PROGRAM VERIFY Modes and must be at +5V in all other modes.
MK2716 ERASING PROCEDURE
The MK2716 may be erased by exposure to high intensity ultraviolet light, illuminating the chip thru the transparent window. This exposure to ultraviolet light induces the flow of a photo current from the floating gate thereby discharging the gate to its initial state. An ultraviolet source of 2537A yielding a total integrated dosage of 15 Watt-seconds/cm2 is required. Note that all bits of the MK2716 will be erased. The erasure time is approximately 15 to 20 mi"nutes utilizing a ultra-violet lamp with a 12000IlW/cm2 power rating. The lamp should be used without short wave filters, and the MK2716 to be erased should be placed about one inch away from the lamp tubes. It should be noted that as the distance between the lamp and the chip is doubled, the exposure time required goes up bya factor of 4. The UV content of sunlight is insufficient to provide a practical means of erasing the MK2716. However, it is not recommended thatthe MK2716 tie operated or stored in direct sunlight, as the UV content of sunlight may cause erasure of some bits in a short period of time.